Passenger-car body painting at 23 JPH — four GR6150-2900 robots with rotary bells
Four CMA GR6150-2900 robots (ATEX Zone 1/21) paint car bodies at 23 jobs per hour from two opposed stations with conveyor tracking, using electrostatic rotary bells, servo gear-pump metering and 5-colour change. Delivered eight weeks after deposit and commissioned on site; the customer later re-ordered 13 spare-part items.
The problem the customer brought
Not enough skilled operators, a manual process that was hard to manage, and finish quality that was hard to control.
Workpiece
Car bodies and large body panels, line rate 23 JPH (jobs per hour).
Robots
4 × CMA GR6150-2900 (ATEX Zone 1/21, 15 kg hollow wrist, 2,900 mm reach, high-speed counter card for tracking).
Process and equipment
Solvent-based 1K. Electrostatic rotary bells (SAMES PPH707 originally quoted; the customer selected a domestic JH-A2000 with 0–100 kV control, dual shaping air and a 55 mm cup), 4.5 cc gear-pump servo metering, 5-colour change valve and hold-pressure valve. Two opposed stations with conveyor encoder tracking. One process control cabinet per robot (S7-1500 with proportional valves, valve island and remote I/O) plus two cell control cabinets on 1500F safety PLCs — all pre-integrated in China, with the bells pre-commissioned before shipment.
Pre-integration and factory acceptance test
Safety logic proven, robot paths run on the parts, electrical circuits and every connection checked, equipment inspected point by point before crating.
Delivery and site work
EXW Wuhu; road transport to the customer. On-site work by the customer's team: 30 days.
Commercial terms
Lead time 8 weeks after deposit; site commissioning in month 5.
Shipping terms on current projects: EXW, FOB, CIF or DAP. Customer names, plant locations and prices are not published.
Result
Delivered and commissioned on site; the customer subsequently re-ordered 13 spare-part items (air bearings, gear-pump bodies, high-voltage controllers, atomiser assemblies). Two serious faults appeared during commissioning: axis-2 encoder jitter, and an R11 encoder failure that shifted the path 100 mm in Z. The fault was traced step by step — magnet ring, axis-2 motor, inter-disc cabling, drive, dress pack — and cleared. In continuous production the line has since painted more than 50,000 car bodies.
What we do differently because of this project
Bell cup size and cycle time are locked before the quotation goes out — a 55 mm cup had to be replaced with a 65 mm cup on site. Every interface condition (conveyor encoder type, main-line supply back-pressure, compressed-air pressure and dew point) now goes into a customer-interface list, because hold-pressure valves, cleaning tanks and air treatment all became change orders and the offer was revised three times.